[mirror_ubuntu-kernels.git] / drivers / watchdog / wdt977.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	Wdt977	0.04:	A Watchdog Device for Netwinder W83977AF chip
 *
 *	(c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
 *
 *			-----------------------
 *
 *			-----------------------
 *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
 *           Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *	19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
 *	06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
 *				    from minutes to seconds.
 *      07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
 *                                    nwwatchdog_init.
 *      25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
 *				    remove limitiation to be used on
 *				    Netwinders only
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#include <asm/mach-types.h>

#define WATCHDOG_VERSION  "0.04"
#define WATCHDOG_NAME     "Wdt977"

#define IO_INDEX_PORT	0x370		/* on some systems it can be 0x3F0 */
#define IO_DATA_PORT	(IO_INDEX_PORT + 1)

#define UNLOCK_DATA	0x87
#define LOCK_DATA	0xAA
#define DEVICE_REGISTER	0x07


#define	DEFAULT_TIMEOUT	60			/* default timeout in seconds */

static	int timeout = DEFAULT_TIMEOUT;
static	int timeoutM;				/* timeout in minutes */
static	unsigned long timer_alive;
static	int testmode;
static	char expect_close;
static	DEFINE_SPINLOCK(spinlock);

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
				__MODULE_STRING(DEFAULT_TIMEOUT) ")");
module_param(testmode, int, 0);
MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

/*
 * Start the watchdog
 */

static int wdt977_start(void)
{
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
	 * F2 has the timeout in minutes
	 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
	 *   at timeout, and to reset timer on kbd/mouse activity (not impl.)
	 * F4 is used to just clear the TIMEOUT'ed state (bit 0)
	 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(timeoutM, IO_DATA_PORT);
	outb_p(0xF3, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);	/* another setting is 0E for
					   kbd/mouse/LED */
	outb_p(0xF4, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);

	/* At last select device Aux1 (dev=7) and set GP16 as a
	 * watchdog output. In test mode watch the bit 1 on F4 to
	 * indicate "triggered"
	 */
	if (!testmode) {
		outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
		outb_p(0x07, IO_DATA_PORT);
		outb_p(0xE6, IO_INDEX_PORT);
		outb_p(0x08, IO_DATA_PORT);
	}

	/* lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);
	pr_info("activated\n");

	return 0;
}

/*
 * Stop the watchdog
 */

static int wdt977_stop(void)
{
	unsigned long flags;
	spin_lock_irqsave(&spinlock, flags);

	/* unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
	* F3 is reset to its default state
	* F4 can clear the TIMEOUT'ed state (bit 0) - back to default
	* We can not use GP17 as a PowerLed, as we use its usage as a RedLed
	*/
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(0xFF, IO_DATA_PORT);
	outb_p(0xF3, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(0x00, IO_DATA_PORT);

	/* at last select device Aux1 (dev=7) and set
	   GP16 as a watchdog output */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x07, IO_DATA_PORT);
	outb_p(0xE6, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);

	/* lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);
	pr_info("shutdown\n");

	return 0;
}

/*
 * Send a keepalive ping to the watchdog
 * This is done by simply re-writing the timeout to reg. 0xF2
 */

static int wdt977_keepalive(void)
{
	unsigned long flags;
	spin_lock_irqsave(&spinlock, flags);

	/* unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/* select device Aux2 (device=8) and kicks watchdog reg F2 */
	/* F2 has the timeout in minutes */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF2, IO_INDEX_PORT);
	outb_p(timeoutM, IO_DATA_PORT);

	/* lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);
	spin_unlock_irqrestore(&spinlock, flags);

	return 0;
}

/*
 * Set the watchdog timeout value
 */

static int wdt977_set_timeout(int t)
{
	int tmrval;

	/* convert seconds to minutes, rounding up */
	tmrval = (t + 59) / 60;

	if (machine_is_netwinder()) {
		/* we have a hw bug somewhere, so each 977 minute is actually
		 * only 30sec. This limits the max timeout to half of device
		 * max of 255 minutes...
		 */
		tmrval += tmrval;
	}

	if (tmrval < 1 || tmrval > 255)
		return -EINVAL;

	/* timeout is the timeout in seconds, timeoutM is
	   the timeout in minutes) */
	timeout = t;
	timeoutM = tmrval;
	return 0;
}

/*
 * Get the watchdog status
 */

static int wdt977_get_status(int *status)
{
	int new_status;
	unsigned long flags;

	spin_lock_irqsave(&spinlock, flags);

	/* unlock the SuperIO chip */
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
	outb_p(UNLOCK_DATA, IO_INDEX_PORT);

	/* select device Aux2 (device=8) and read watchdog reg F4 */
	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	outb_p(0x08, IO_DATA_PORT);
	outb_p(0xF4, IO_INDEX_PORT);
	new_status = inb_p(IO_DATA_PORT);

	/* lock the SuperIO chip */
	outb_p(LOCK_DATA, IO_INDEX_PORT);

	spin_unlock_irqrestore(&spinlock, flags);

	*status = 0;
	if (new_status & 1)
		*status |= WDIOF_CARDRESET;

	return 0;
}


/*
 *	/dev/watchdog handling
 */

static int wdt977_open(struct inode *inode, struct file *file)
{
	/* If the watchdog is alive we don't need to start it again */
	if (test_and_set_bit(0, &timer_alive))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	wdt977_start();
	return stream_open(inode, file);
}

static int wdt977_release(struct inode *inode, struct file *file)
{
	/*
	 *	Shut off the timer.
	 *	Lock it in if it's a module and we set nowayout
	 */
	if (expect_close == 42) {
		wdt977_stop();
		clear_bit(0, &timer_alive);
	} else {
		wdt977_keepalive();
		pr_crit("Unexpected close, not stopping watchdog!\n");
	}
	expect_close = 0;
	return 0;
}


/*
 *      wdt977_write:
 *      @file: file handle to the watchdog
 *      @buf: buffer to write (unused as data does not matter here
 *      @count: count of bytes
 *      @ppos: pointer to the position to write. No seeks allowed
 *
 *      A write to a watchdog device is defined as a keepalive signal. Any
 *      write of data will do, as we we don't define content meaning.
 */

static ssize_t wdt977_write(struct file *file, const char __user *buf,
			    size_t count, loff_t *ppos)
{
	if (count) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			expect_close = 0;

			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}

		/* someone wrote to us, we should restart timer */
		wdt977_keepalive();
	}
	return count;
}

static const struct watchdog_info ident = {
	.options =		WDIOF_SETTIMEOUT |
				WDIOF_MAGICCLOSE |
				WDIOF_KEEPALIVEPING,
	.firmware_version =	1,
	.identity =		WATCHDOG_NAME,
};

/*
 *      wdt977_ioctl:
 *      @inode: inode of the device
 *      @file: file handle to the device
 *      @cmd: watchdog command
 *      @arg: argument pointer
 *
 *      The watchdog API defines a common set of functions for all watchdogs
 *      according to their available features.
 */

static long wdt977_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	int status;
	int new_options, retval = -EINVAL;
	int new_timeout;
	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(uarg.ident, &ident,
			sizeof(ident)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
		wdt977_get_status(&status);
		return put_user(status, uarg.i);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);

	case WDIOC_SETOPTIONS:
		if (get_user(new_options, uarg.i))
			return -EFAULT;

		if (new_options & WDIOS_DISABLECARD) {
			wdt977_stop();
			retval = 0;
		}

		if (new_options & WDIOS_ENABLECARD) {
			wdt977_start();
			retval = 0;
		}

		return retval;

	case WDIOC_KEEPALIVE:
		wdt977_keepalive();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;

		if (wdt977_set_timeout(new_timeout))
			return -EINVAL;

		wdt977_keepalive();
		fallthrough;

	case WDIOC_GETTIMEOUT:
		return put_user(timeout, uarg.i);

	default:
		return -ENOTTY;

	}
}

static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt977_stop();
	return NOTIFY_DONE;
}

static const struct file_operations wdt977_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wdt977_write,
	.unlocked_ioctl	= wdt977_ioctl,
	.compat_ioctl	= compat_ptr_ioctl,
	.open		= wdt977_open,
	.release	= wdt977_release,
};

static struct miscdevice wdt977_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &wdt977_fops,
};

static struct notifier_block wdt977_notifier = {
	.notifier_call = wdt977_notify_sys,
};

static int __init wd977_init(void)
{
	int rc;

	pr_info("driver v%s\n", WATCHDOG_VERSION);

	/* Check that the timeout value is within its range;
	   if not reset to the default */
	if (wdt977_set_timeout(timeout)) {
		wdt977_set_timeout(DEFAULT_TIMEOUT);
		pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
			DEFAULT_TIMEOUT);
	}

	/* on Netwinder the IOports are already reserved by
	 * arch/arm/mach-footbridge/netwinder-hw.c
	 */
	if (!machine_is_netwinder()) {
		if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
			pr_err("I/O address 0x%04x already in use\n",
			       IO_INDEX_PORT);
			rc = -EIO;
			goto err_out;
		}
	}

	rc = register_reboot_notifier(&wdt977_notifier);
	if (rc) {
		pr_err("cannot register reboot notifier (err=%d)\n", rc);
		goto err_out_region;
	}

	rc = misc_register(&wdt977_miscdev);
	if (rc) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       wdt977_miscdev.minor, rc);
		goto err_out_reboot;
	}

	pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
		timeout, nowayout, testmode);

	return 0;

err_out_reboot:
	unregister_reboot_notifier(&wdt977_notifier);
err_out_region:
	if (!machine_is_netwinder())
		release_region(IO_INDEX_PORT, 2);
err_out:
	return rc;
}

static void __exit wd977_exit(void)
{
	wdt977_stop();
	misc_deregister(&wdt977_miscdev);
	unregister_reboot_notifier(&wdt977_notifier);
	release_region(IO_INDEX_PORT, 2);
}

module_init(wd977_init);
module_exit(wd977_exit);

MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
MODULE_DESCRIPTION("W83977AF Watchdog driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4	2	/*
4dab06fa	3	* Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip
1da177e4 LT	4	*
	5	* (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
	6	*
	7	* -----------------------
	8	*
1da177e4 LT	9	* -----------------------
	10	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	11	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	12	* 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
	13	* 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
	14	* from minutes to seconds.
	15	* 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
	16	* nwwatchdog_init.
4dab06fa	17	* 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
f2b79c6e AC	18	* remove limitiation to be used on
f2b79c6e AC	19	* Netwinders only
1da177e4 LT	20	*/
1da177e4 LT	21
27c766aa JP	22	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	23
1da177e4 LT	24	#include <linux/module.h>
1da177e4 LT	25	#include <linux/moduleparam.h>
1da177e4 LT	26	#include <linux/types.h>
	27	#include <linux/kernel.h>
	28	#include <linux/fs.h>
	29	#include <linux/miscdevice.h>
	30	#include <linux/init.h>
4dab06fa	31	#include <linux/ioport.h>
1da177e4 LT	32	#include <linux/watchdog.h>
	33	#include <linux/notifier.h>
	34	#include <linux/reboot.h>
f2b79c6e AC	35	#include <linux/io.h>
f2b79c6e AC	36	#include <linux/uaccess.h>
1da177e4	37
1da177e4	38	#include <asm/mach-types.h>
1da177e4	39
4dab06fa WS	40	#define WATCHDOG_VERSION "0.04"
4dab06fa WS	41	#define WATCHDOG_NAME "Wdt977"
4dab06fa WS	42
4dab06fa WS	43	#define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */
f2b79c6e	44	#define IO_DATA_PORT (IO_INDEX_PORT + 1)
4dab06fa WS	45
	46	#define UNLOCK_DATA 0x87
	47	#define LOCK_DATA 0xAA
	48	#define DEVICE_REGISTER 0x07
	49
1da177e4 LT	50
	51	#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */
	52
	53	static int timeout = DEFAULT_TIMEOUT;
	54	static int timeoutM; /* timeout in minutes */
	55	static unsigned long timer_alive;
	56	static int testmode;
	57	static char expect_close;
c7dfd0cc	58	static DEFINE_SPINLOCK(spinlock);
1da177e4 LT	59
1da177e4 LT	60	module_param(timeout, int, 0);
76550d32	61	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
f2b79c6e	62	__MODULE_STRING(DEFAULT_TIMEOUT) ")");
1da177e4	63	module_param(testmode, int, 0);
f2b79c6e	64	MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
1da177e4	65
86a1e189 WVS	66	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	67	module_param(nowayout, bool, 0);
f2b79c6e AC	68	MODULE_PARM_DESC(nowayout,
	69	"Watchdog cannot be stopped once started (default="
	70	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	71
	72	/*
	73	* Start the watchdog
	74	*/
	75
	76	static int wdt977_start(void)
	77	{
4dab06fa WS	78	unsigned long flags;
	79
	80	spin_lock_irqsave(&spinlock, flags);
	81
1da177e4	82	/* unlock the SuperIO chip */
4dab06fa WS	83	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
4dab06fa WS	84	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
1da177e4 LT	85
	86	/* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
	87	* F2 has the timeout in minutes
	88	* F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
	89	* at timeout, and to reset timer on kbd/mouse activity (not impl.)
	90	* F4 is used to just clear the TIMEOUT'ed state (bit 0)
	91	*/
4dab06fa WS	92	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	93	outb_p(0x08, IO_DATA_PORT);
	94	outb_p(0xF2, IO_INDEX_PORT);
	95	outb_p(timeoutM, IO_DATA_PORT);
	96	outb_p(0xF3, IO_INDEX_PORT);
f2b79c6e AC	97	outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for
f2b79c6e AC	98	kbd/mouse/LED */
4dab06fa WS	99	outb_p(0xF4, IO_INDEX_PORT);
4dab06fa WS	100	outb_p(0x00, IO_DATA_PORT);
1da177e4	101
f2b79c6e AC	102	/* At last select device Aux1 (dev=7) and set GP16 as a
	103	* watchdog output. In test mode watch the bit 1 on F4 to
	104	* indicate "triggered"
	105	*/
	106	if (!testmode) {
4dab06fa WS	107	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	108	outb_p(0x07, IO_DATA_PORT);
	109	outb_p(0xE6, IO_INDEX_PORT);
	110	outb_p(0x08, IO_DATA_PORT);
1da177e4 LT	111	}
	112
	113	/* lock the SuperIO chip */
4dab06fa	114	outb_p(LOCK_DATA, IO_INDEX_PORT);
1da177e4	115
4dab06fa	116	spin_unlock_irqrestore(&spinlock, flags);
27c766aa	117	pr_info("activated\n");
1da177e4 LT	118
	119	return 0;
	120	}
	121
	122	/*
	123	* Stop the watchdog
	124	*/
	125
	126	static int wdt977_stop(void)
	127	{
4dab06fa WS	128	unsigned long flags;
	129	spin_lock_irqsave(&spinlock, flags);
	130
1da177e4	131	/* unlock the SuperIO chip */
4dab06fa WS	132	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
4dab06fa WS	133	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
1da177e4 LT	134
	135	/* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
	136	* F3 is reset to its default state
	137	* F4 can clear the TIMEOUT'ed state (bit 0) - back to default
	138	* We can not use GP17 as a PowerLed, as we use its usage as a RedLed
	139	*/
4dab06fa WS	140	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	141	outb_p(0x08, IO_DATA_PORT);
	142	outb_p(0xF2, IO_INDEX_PORT);
	143	outb_p(0xFF, IO_DATA_PORT);
	144	outb_p(0xF3, IO_INDEX_PORT);
	145	outb_p(0x00, IO_DATA_PORT);
	146	outb_p(0xF4, IO_INDEX_PORT);
	147	outb_p(0x00, IO_DATA_PORT);
	148	outb_p(0xF2, IO_INDEX_PORT);
	149	outb_p(0x00, IO_DATA_PORT);
1da177e4	150
f2b79c6e AC	151	/* at last select device Aux1 (dev=7) and set
f2b79c6e AC	152	GP16 as a watchdog output */
4dab06fa WS	153	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	154	outb_p(0x07, IO_DATA_PORT);
	155	outb_p(0xE6, IO_INDEX_PORT);
	156	outb_p(0x08, IO_DATA_PORT);
1da177e4 LT	157
1da177e4 LT	158	/* lock the SuperIO chip */
4dab06fa	159	outb_p(LOCK_DATA, IO_INDEX_PORT);
1da177e4	160
4dab06fa	161	spin_unlock_irqrestore(&spinlock, flags);
27c766aa	162	pr_info("shutdown\n");
1da177e4 LT	163
	164	return 0;
	165	}
	166
	167	/*
	168	* Send a keepalive ping to the watchdog
	169	* This is done by simply re-writing the timeout to reg. 0xF2
	170	*/
	171
	172	static int wdt977_keepalive(void)
	173	{
4dab06fa WS	174	unsigned long flags;
	175	spin_lock_irqsave(&spinlock, flags);
	176
1da177e4	177	/* unlock the SuperIO chip */
4dab06fa WS	178	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
4dab06fa WS	179	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
1da177e4 LT	180
	181	/* select device Aux2 (device=8) and kicks watchdog reg F2 */
	182	/* F2 has the timeout in minutes */
4dab06fa WS	183	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	184	outb_p(0x08, IO_DATA_PORT);
	185	outb_p(0xF2, IO_INDEX_PORT);
	186	outb_p(timeoutM, IO_DATA_PORT);
1da177e4 LT	187
1da177e4 LT	188	/* lock the SuperIO chip */
4dab06fa WS	189	outb_p(LOCK_DATA, IO_INDEX_PORT);
4dab06fa WS	190	spin_unlock_irqrestore(&spinlock, flags);
1da177e4 LT	191
	192	return 0;
	193	}
	194
	195	/*
	196	* Set the watchdog timeout value
	197	*/
	198
	199	static int wdt977_set_timeout(int t)
	200	{
	201	int tmrval;
	202
	203	/* convert seconds to minutes, rounding up */
	204	tmrval = (t + 59) / 60;
	205
	206	if (machine_is_netwinder()) {
f2b79c6e AC	207	/* we have a hw bug somewhere, so each 977 minute is actually
	208	* only 30sec. This limits the max timeout to half of device
	209	* max of 255 minutes...
1da177e4 LT	210	*/
	211	tmrval += tmrval;
	212	}
	213
f2b79c6e	214	if (tmrval < 1 \|\| tmrval > 255)
1da177e4 LT	215	return -EINVAL;
1da177e4 LT	216
f2b79c6e AC	217	/* timeout is the timeout in seconds, timeoutM is
f2b79c6e AC	218	the timeout in minutes) */
1da177e4 LT	219	timeout = t;
	220	timeoutM = tmrval;
	221	return 0;
	222	}
	223
	224	/*
	225	* Get the watchdog status
	226	*/
	227
	228	static int wdt977_get_status(int *status)
	229	{
	230	int new_status;
4dab06fa	231	unsigned long flags;
1da177e4	232
4dab06fa	233	spin_lock_irqsave(&spinlock, flags);
1da177e4 LT	234
1da177e4 LT	235	/* unlock the SuperIO chip */
4dab06fa WS	236	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
4dab06fa WS	237	outb_p(UNLOCK_DATA, IO_INDEX_PORT);
1da177e4 LT	238
1da177e4 LT	239	/* select device Aux2 (device=8) and read watchdog reg F4 */
4dab06fa WS	240	outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
	241	outb_p(0x08, IO_DATA_PORT);
	242	outb_p(0xF4, IO_INDEX_PORT);
	243	new_status = inb_p(IO_DATA_PORT);
1da177e4 LT	244
1da177e4 LT	245	/* lock the SuperIO chip */
4dab06fa	246	outb_p(LOCK_DATA, IO_INDEX_PORT);
1da177e4	247
4dab06fa WS	248	spin_unlock_irqrestore(&spinlock, flags);
4dab06fa WS	249
f2b79c6e	250	*status = 0;
1da177e4 LT	251	if (new_status & 1)
	252	*status \|= WDIOF_CARDRESET;
	253
	254	return 0;
	255	}
	256
	257
	258	/*
	259	* /dev/watchdog handling
	260	*/
	261
	262	static int wdt977_open(struct inode inode, struct file file)
	263	{
	264	/* If the watchdog is alive we don't need to start it again */
f2b79c6e	265	if (test_and_set_bit(0, &timer_alive))
1da177e4 LT	266	return -EBUSY;
	267
	268	if (nowayout)
	269	__module_get(THIS_MODULE);
	270
	271	wdt977_start();
c5bf68fe	272	return stream_open(inode, file);
1da177e4 LT	273	}
	274
	275	static int wdt977_release(struct inode inode, struct file file)
	276	{
	277	/*
	278	* Shut off the timer.
5f3b2756	279	* Lock it in if it's a module and we set nowayout
1da177e4	280	*/
f2b79c6e	281	if (expect_close == 42) {
1da177e4	282	wdt977_stop();
f2b79c6e	283	clear_bit(0, &timer_alive);
1da177e4	284	} else {
1da177e4	285	wdt977_keepalive();
27c766aa	286	pr_crit("Unexpected close, not stopping watchdog!\n");
1da177e4 LT	287	}
	288	expect_close = 0;
	289	return 0;
	290	}
	291
	292
	293	/*
	294	* wdt977_write:
	295	* @file: file handle to the watchdog
	296	* @buf: buffer to write (unused as data does not matter here
	297	* @count: count of bytes
	298	* @ppos: pointer to the position to write. No seeks allowed
	299	*
	300	* A write to a watchdog device is defined as a keepalive signal. Any
	301	* write of data will do, as we we don't define content meaning.
	302	*/
	303
	304	static ssize_t wdt977_write(struct file file, const char __user buf,
	305	size_t count, loff_t *ppos)
	306	{
f2b79c6e AC	307	if (count) {
f2b79c6e AC	308	if (!nowayout) {
1da177e4 LT	309	size_t i;
	310
	311	/* In case it was set long ago */
	312	expect_close = 0;
	313
f2b79c6e	314	for (i = 0; i != count; i++) {
1da177e4 LT	315	char c;
	316	if (get_user(c, buf + i))
	317	return -EFAULT;
	318	if (c == 'V')
	319	expect_close = 42;
	320	}
	321	}
	322
4dab06fa	323	/* someone wrote to us, we should restart timer */
1da177e4 LT	324	wdt977_keepalive();
	325	}
	326	return count;
	327	}
	328
f2b79c6e AC	329	static const struct watchdog_info ident = {
	330	.options = WDIOF_SETTIMEOUT \|
	331	WDIOF_MAGICCLOSE \|
	332	WDIOF_KEEPALIVEPING,
	333	.firmware_version = 1,
	334	.identity = WATCHDOG_NAME,
	335	};
	336
1da177e4 LT	337	/*
	338	* wdt977_ioctl:
	339	* @inode: inode of the device
	340	* @file: file handle to the device
	341	* @cmd: watchdog command
	342	* @arg: argument pointer
	343	*
	344	* The watchdog API defines a common set of functions for all watchdogs
	345	* according to their available features.
	346	*/
	347
f2b79c6e AC	348	static long wdt977_ioctl(struct file *file, unsigned int cmd,
f2b79c6e AC	349	unsigned long arg)
1da177e4 LT	350	{
	351	int status;
	352	int new_options, retval = -EINVAL;
	353	int new_timeout;
	354	union {
	355	struct watchdog_info __user *ident;
	356	int __user *i;
	357	} uarg;
	358
	359	uarg.i = (int __user *)arg;
	360
f2b79c6e	361	switch (cmd) {
1da177e4 LT	362	case WDIOC_GETSUPPORT:
	363	return copy_to_user(uarg.ident, &ident,
	364	sizeof(ident)) ? -EFAULT : 0;
	365
	366	case WDIOC_GETSTATUS:
	367	wdt977_get_status(&status);
	368	return put_user(status, uarg.i);
	369
	370	case WDIOC_GETBOOTSTATUS:
	371	return put_user(0, uarg.i);
	372
1da177e4	373	case WDIOC_SETOPTIONS:
f2b79c6e	374	if (get_user(new_options, uarg.i))
1da177e4 LT	375	return -EFAULT;
	376
	377	if (new_options & WDIOS_DISABLECARD) {
	378	wdt977_stop();
	379	retval = 0;
	380	}
	381
	382	if (new_options & WDIOS_ENABLECARD) {
	383	wdt977_start();
	384	retval = 0;
	385	}
	386
	387	return retval;
	388
0c06090c WVS	389	case WDIOC_KEEPALIVE:
	390	wdt977_keepalive();
	391	return 0;
	392
1da177e4 LT	393	case WDIOC_SETTIMEOUT:
	394	if (get_user(new_timeout, uarg.i))
	395	return -EFAULT;
	396
	397	if (wdt977_set_timeout(new_timeout))
143a2e54	398	return -EINVAL;
1da177e4 LT	399
1da177e4 LT	400	wdt977_keepalive();
bd490f82	401	fallthrough;
1da177e4 LT	402
	403	case WDIOC_GETTIMEOUT:
	404	return put_user(timeout, uarg.i);
	405
0c06090c WVS	406	default:
	407	return -ENOTTY;
	408
1da177e4 LT	409	}
	410	}
	411
	412	static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
	413	void *unused)
	414	{
f2b79c6e	415	if (code == SYS_DOWN \|\| code == SYS_HALT)
1da177e4 LT	416	wdt977_stop();
	417	return NOTIFY_DONE;
	418	}
	419
f2b79c6e	420	static const struct file_operations wdt977_fops = {
1da177e4 LT	421	.owner = THIS_MODULE,
	422	.llseek = no_llseek,
	423	.write = wdt977_write,
f2b79c6e	424	.unlocked_ioctl = wdt977_ioctl,
b6dfb247	425	.compat_ioctl = compat_ptr_ioctl,
1da177e4 LT	426	.open = wdt977_open,
	427	.release = wdt977_release,
	428	};
	429
f2b79c6e	430	static struct miscdevice wdt977_miscdev = {
1da177e4 LT	431	.minor = WATCHDOG_MINOR,
	432	.name = "watchdog",
	433	.fops = &wdt977_fops,
	434	};
	435
	436	static struct notifier_block wdt977_notifier = {
	437	.notifier_call = wdt977_notify_sys,
	438	};
	439
4dab06fa	440	static int __init wd977_init(void)
1da177e4	441	{
4dab06fa WS	442	int rc;
4dab06fa WS	443
27c766aa	444	pr_info("driver v%s\n", WATCHDOG_VERSION);
4dab06fa	445
f2b79c6e AC	446	/* Check that the timeout value is within its range;
	447	if not reset to the default */
	448	if (wdt977_set_timeout(timeout)) {
1da177e4	449	wdt977_set_timeout(DEFAULT_TIMEOUT);
27c766aa JP	450	pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
27c766aa JP	451	DEFAULT_TIMEOUT);
1da177e4 LT	452	}
1da177e4 LT	453
4dab06fa WS	454	/* on Netwinder the IOports are already reserved by
	455	* arch/arm/mach-footbridge/netwinder-hw.c
	456	*/
f2b79c6e AC	457	if (!machine_is_netwinder()) {
f2b79c6e AC	458	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
27c766aa JP	459	pr_err("I/O address 0x%04x already in use\n",
27c766aa JP	460	IO_INDEX_PORT);
4dab06fa WS	461	rc = -EIO;
	462	goto err_out;
	463	}
1da177e4 LT	464	}
1da177e4 LT	465
c6cb13ae	466	rc = register_reboot_notifier(&wdt977_notifier);
f2b79c6e	467	if (rc) {
27c766aa	468	pr_err("cannot register reboot notifier (err=%d)\n", rc);
4dab06fa WS	469	goto err_out_region;
	470	}
	471
c6cb13ae	472	rc = misc_register(&wdt977_miscdev);
f2b79c6e	473	if (rc) {
27c766aa JP	474	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
27c766aa JP	475	wdt977_miscdev.minor, rc);
c6cb13ae	476	goto err_out_reboot;
1da177e4 LT	477	}
1da177e4 LT	478
27c766aa JP	479	pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
27c766aa JP	480	timeout, nowayout, testmode);
1da177e4 LT	481
1da177e4 LT	482	return 0;
4dab06fa	483
c6cb13ae WVS	484	err_out_reboot:
c6cb13ae WVS	485	unregister_reboot_notifier(&wdt977_notifier);
4dab06fa WS	486	err_out_region:
4dab06fa WS	487	if (!machine_is_netwinder())
f2b79c6e	488	release_region(IO_INDEX_PORT, 2);
4dab06fa WS	489	err_out:
4dab06fa WS	490	return rc;
1da177e4 LT	491	}
1da177e4 LT	492
4dab06fa	493	static void __exit wd977_exit(void)
1da177e4	494	{
4dab06fa	495	wdt977_stop();
1da177e4 LT	496	misc_deregister(&wdt977_miscdev);
1da177e4 LT	497	unregister_reboot_notifier(&wdt977_notifier);
f2b79c6e	498	release_region(IO_INDEX_PORT, 2);
1da177e4 LT	499	}
1da177e4 LT	500
4dab06fa WS	501	module_init(wd977_init);
4dab06fa WS	502	module_exit(wd977_exit);
1da177e4	503
4dab06fa	504	MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
1da177e4 LT	505	MODULE_DESCRIPTION("W83977AF Watchdog driver");
1da177e4 LT	506	MODULE_LICENSE("GPL");